Fluid transducer



H. SCHOTTLER FLUID TRANSDUCER oct. 1, 1968 Filed April 4. 1966 H. scHoTTLER FLUID TRANSDUCER ocr. 1*, 1968 5 Sheets-Sheet 2 Filed April 4. 1966 INVENTOR HENRYSCHOTTLER WMN. mh

N61 ,ASQ NMN www w ,NMN @NEN mwN @6N 6N kw: ,NSQWMMN NMNQMW H. SCHOTTLER FLUID 'TRAN SDUCER Oct. 1, 1968 5 Sheets-Sheet 3 Filed April 4, 1966 QNN.

wml,

QWN

www

INVENTOR HENRY SCHOTTLER Oct. l, 1968 H. scHoTTLER 3,403,668

FLUID TRANSDUCER Filed April 4, 1966 5 sheets-sheet 4 0 3201 f4/ fz 35 .370

H. SCHOTTLER FLUID TMNSDUCER Oct. l, 1968 5 Sheets-Sheet 5 Filed April 4, 1966 United States Patent O 3,403,668 FLUID TRANSDUCER Henry Schottler, 8008 Country Club Lane, North Riverside, Ill. 60546 Filed Apr. 4, 1966, Ser. No. 540,003 19 Claims. (Cl. 12S-197) ABSTRACT OF THE DISCLOSURE A fluid transducer including a reciprocatory piston member in a cylinder; a rotary power member; a drive mechanism including a cam joined to a piston member and a rcam joined to a rotary power member. Each cam has an opposed cam surface projecting toward the other cam. Rolling means is in frictional engagement with the opposed cam surfaces. Means are provided for permitting the rolling means to orbit between the opposed cam surfaces while rolling along each of the opposed cam surfaces as the piston member reciprocates with respect to the rotary power member.

This invention relates generally to fluid translucers, and more particularly relates to uid transducers incorporating a drive mechanism for converting rotary motion to reciprocatory motion.

An object of this invention is to provide a uid transducer which is adaptable for use as an engine, hydraulic motor, compressor, pump or the like.

Another object is to provide a fluid transducer wherein reciprocatory motion is directly converted into rotary motion, or vice versa, by a drive mechanism.

A yfurther object is to provide a fluid transducer with a drive mechanism which can be readily adapted to vary the output or fluid displacement characteristics of the transducer.

A still -further object is to provide a fluid transducer of compact construction which has a very high loading capacity and high mechanical and volumetric eticiencies.

This invention generally comprises a iluid transducer of compact construction which includes a drive mechanism for converting reciprocating motion directly to rotary motion, and vice versa. The drive mechanism in accordance `with this invention therefore eliminates the need for providing the transducer with piston crank shafts, connecting rods and the like, and increases the efiiciency and loading capacity of the transducer. The transducer incorporating the drive of this invention is also readily adaptable for operation with variable output or uid displacement characteristics.

Additional objects and features of this invention will become readily apparent from the following description of embodiments thereof, taken in conjunution with the accompanying drawings, wherein:

FIGURE l is a vertical sectional View of a piston-type uid transducer embodying the features of the present invention;

FIGURE 2 is an enlarged cross-sectional view taken along the line 2 2 in FIGURE l;

FIGURES 3A, 3B and 3C are plane developed views of the drive mechanism in accordance with this invention, shown in three different operating positions;

FIGURE 4 is a perspective view of a compressor or pump embodying the features of this invention;

FIGURE 5 is an enlarged vertical sectional view of a portion of the compressor or pump shown in FIGURE 4;

FIGURE 6 is a cross-sectional view taken along the line 6 6 in FIGURE 5;

FIGURE 7 is a cross-sectional view taken along line 7 7 in FIGURE 5;

the

ICE

FIGURE 8 is a cross-sectional view taken along the line 8 8 in FIGURE 5;

FIGURE 9 is a plane developed view of the drive mechanism of the pump or compressor illustrated in FIG- URES 4 through 8;

FIGURE 10 is a vertical sectional view of an internal combustion engine embodying the features of this invention, showing the engine pistons in an advanced -position;

FIGURE 1l is a vertical sectional view of the internal combustion engine illustrated in FIGURE 10, showing the engine pistons in a retracted position;

FIGURE 12 is a cross-sectional view taken along the line 12-12 in FIGURE 10;

FIGURE 13 is a cross-sectional view taken along the line 13 13 in FIGURE 10;

FIGURE 14 is a cross-sectional View taken along the line 14 14 in FIGURE 10; and

FIGURE 15 is a cross-sectional view taken along the line 15 15 in FIGURE l0.

Transducer construction and Operation Referring now to the drawings, and more particularly to FIGURES l through 3, there is illustrated a pistontype fluid transducer embodying the features of the present invention and indicated generally lby the reference numeral 20. The fluid transducer includes an upper housing 21a, defining a cylindrical uid chamber 22, and a piston member 23 which is capable of reciprocation within the chamber 22. The housing 21 is provided with suitable valving means 24 which permit fluid, either gaseous or liquid, to enter and exhaust 'from the chamber 22, and the piston 23 is provided with suitable piston rings 25 for sealing the fluid in chamber 22. The housing 21 may also include a spark plug 26 extending into the chamber 22, if the transducer 20 is to be employed as an internal combustion engine. Furthermore, the transducer 20 includes a rotatable power shaft which is operably joined to the transducer piston 23 lby means of a drive mechanism, generally indicated by the reference numeral 50.

When the transducer 20 is employed as a pump or compressor, a fluid is admitted into the chamber 22 by the valve means 24, and the power shaft 40 is rotated by a suitable power source (not shown). The rotating power shaft 40 operates through the drive mechanism 50 to directly reciprocate the piston 23 within the chamber 22. The transducer 20 will thereby transmit a pumping or compressive force to the fluid contained within the chamber 22. When the transducer 20 is employed as an internal combustion engine the valve means 24 is operated by any suitable means (not shown) to admit a charge of fuel and air into the chamber 22. The charge is then ignited by means of a spark plug 26 to drive the piston 23 through a power stroke, in a downward direction as viewed in FIGURE 1. The reciprocating motion of the piston 23 will then operate through the drive mechanism to rotate the power shaft 40.

More specifically, the power shaft 40 is rotatably sup ported by a lower housing portion 2lb within a suitable thrust bearing 41. Bolts 42 are provided to removably secure the lower housing portion 2lb to the upper housing 21a so that the transducer 20 can be readily disassembled for inspection and repair. The power shaft 40 also has an integral stud shaft 43 which extends upwardly from the power shaft 40 into the upper housing 21a.

As seen in FIGURES l and 2, the drive mechanism 50, which operatively connects the piston 23 to the power shaft 40, includes a pair of cam races 51 and 52 spaced in an opposed relationship with respect to each other. The cams 51 and 52 are preferably formed from hardened steel or other suitable material so that the cams 51 and 52 present opposed cam surfaces 51a and 52u which are long-wearing. As seen in FIGURE 3, the cam surfaces 51a and 52a are provided with one or more inwardlyextending proturberances or lobes 53 and 54, respectively, having an angle of inclination or cam angle X, In this embodiment, the cam 51 includes three lobes 53 and the cam 52 likewise includes three lobes 54. In addition, the lobes 53 and 54 are uniformly spaced at one hundred and twenty degrees about the circumference of the respective cams 51 and 52, and are of equal amplitud-e and wave length, and are preferably provided with uniform curvature. The' amplitude of the lobes 53 and 54 is generally indicated as A, and the lobe wave length as L, in FIGURE 3. Thus, as seen from the plane developments in FIGURES 3A, 3B and 3C, the lobes 53 and 54 provide the opposed surfaces of the cams 51 and 52 with a substantially sinusoidal configuration.

The ydrive mechanism 50 further includes a set of rolling members or balls 60 positioned between the opposed surfaces 51a and 52a of the cams 51 and 52 in frictional rolling engagement with the cam lobes 53 and 54. The balls 60 are also preferably made of a strong-wearing material such as hardened steel. One or more of such rolling members 60 may be used, and the position of the rolling members 6) may be varied to suit particular ap plications. However, for stable and efficient operation of the transducer 20, it is preferred that the drive mechanasm 50 be provided with three balls 60 uniformly spaced between the three-lobed cams 51 and 52. As seen in FIG- URE 2, the uniform positioning of the balls 60 is arranged by placing the balls 60 in a ball retainer 61 provided with ball race apertures 62. The dimensions of the rolling members or balls `60 may be varied, if desired, as long as the rolling members 60 are of sufficient size with respect to the amplitude A of the lobes 53 and 54 to prevent substantial engagement between the opposed cams 51 and 52 or between the cams 51 and 52 and the ball retainer 61.

In order to connect the transducer piston 23 to the power shaft 40 by means of the drive mechanism 50, the upper cam 52, as seen in FIGURE l, is secured to the lower end of the piston 23 by suitable means such as bolts 63. The sides of cam 52 are provided with grooves 64 which engage with adjacent splines 65 provided within the transducer housing 21. By such an arrangement, the cam 52 will reciprocate within the housing 21 in unison with the piston 23, and the cooperation of the grooves 64 and splines 65 prevent the cams 52 and the piston 23 from rotating. The lower cam 51, as seen in FIGURE 1, is fixed to the power shaft 40 concentrically with respect to the opposed cam 52, and is not otherwise restrained. Therefore, the cam 51 will rotate with the power shaft 40.

The connection between the piston 23 and the power shaft 40 is completed by securing the balls 60 in frictional rolling engagement between the opposed concentric cams 51 and 52. This is accomplished in this embodiment by providing the center of the ball retainer 61 with a sleeve bushing 70, and securing the bushing 70 around the upwardly extending stud shaft 43. A clip ring 71 prevents the retainer 61 from becoming disengaged from the stud shaft 43, but the bushing 70 permits the retainer 61 to freely rotate and slide axially on the stud shaft 43. The transducer is also provided with suitable means such as compression springs 72, mounted between a housing flange 73 and the cam 52, to bias the cams 51 and 52 together against the balls 60.

As seen in FIGURES l and 3A, the piston 23 is positioned within the chamber 22 so that the extreme upward position of the piston 23 occurs when the balls 60 move between the opposed lobes 53 and 54 of the cams 51 and 52. The extreme downward position of the piston 23 within the chamber 22 occurs when the balls 60 are moved between the lobes 53 and 54 on the cams 51 and 52, as seen in FIGURE 3C. Since the amplitude A of each lobe 53 and 54 is equal in this embodiment, the length of the stroke through which the piston 23 reciprocates will therefore equal twice the amplitude A of the cam lobes 53 and 54, or 2A.

To employ the transducer 20 as a fluid pump or compressor, the spark plug 26 is omitted, and the Valving means 24 is connected to a fluid source and a fluid exhaust reservoir by any suitable means (not shown). In addition, suitable means (not shown) are provided to operate the valving means 24 in the proper sequence for admitting and exhausting the fluid under treatment into or out of the piston chamber 22. The operation of the transducer 20 as a pump or compressor is then begun by rotating the power shaft 40 at the desired speed by any suitable power source (not shown). For purposes of illustration, the power shaft 40 is rotated in a clockwise direction as viewed in FIGURES 1 and 2.

The rotation of the power shaft 40 in a clockwise direction also rotates the connected cam 51 in the same direction and at the same speed. The cam 51 is thereby rotatably advanced with respect to the nonrotatable cam 52. in a leftward direction in FIGURES 3A, 3B and 3C. Since the lobes 53 and 54 on the opposed cams 51 and 52 are of equal wave length L, and are uniformly spaced one hundred and twenty degrees apart, the rotation of the power shaft 40 through one hundred and twenty degrees will advance the cam 51 one wave length L with respect to the opposed cam 52. The resulting movement of the cam 51 is from an initial position seen in FIGURE 3A, through an intermediate position seen in FIGURE 3B, to a final position seen in FIG. 3C. Of course, the continued rotation of the power shaft 40 will cause the cam 51 to advance one wave length L degrees) with respect to the cam 52 three times for each three hundred and sixty degree revolution of the power shaft 40.

As previously described, the balls 60 of the drive mechanism 50 can rotate within their respective apertures 62, and the ball retainer 61 can move axially or rotatably on the stud shaft 43. The advancement of cam 51 with respect to the opposed cam 52 will therefore cause the balls 60, frictionally engaged between the cams S1 and 52, to roll along the opposed surfaces 51a and 52a of the cams 51 and 52, and over the cam lobes 53 and 54. The direction of rotation of the balls 60 within their apertures 62 is indicated by arrows in FIGURES 3A, 3B and 3C. The ball retainer 61 will simultaneously rotate and slide axially on the stud shaft 43, and permit balls 60 to follow the curvature of the opposed cam lobes 53 and 54. Since the balls 60 are in constant rolling engagement with the opposed cam surfaces 51a and 52a, the advancement of the cam 51 through one lobe wave length L will advance the balls 60 along the cams 51 and 52 a distance equal to one-half of a lobe wave length (1/2 L or 60 degrees), from an upward position engaged with the lobes 53 and 54, as seen in FIGURE 3A, to a downward position between the lobes 53 and 54, as seen in FIGURE 3C. Again, the rolling of the balls 60 from the position shown in FIG- URE 3A to the position shown in FIGURE 3C will occur three times for each revolution of shaft 40, since the lobe wave length L in this embodiment is one hundred and twenty degrees.

Referring to FIGURE l, the rolling of the balls 60 induced by the rotation of the cam 51 will permit the cornpression springs 72 to move the cam 52 and the attached piston 23 downwardly when the balls 60 begin to move downwardly between the cam lobes 53 and 54. Thus, the movement of the balls 60 from the position seen in FIG- URE 3A toward the downward position seen in FIGURE 3C moves the piston 23 downwardly within the piston chamber 22, and begins the intake stroke of the piston 23. When the transducer 20 is employed as a fluid pump or compressor, the valving means 24 is suitably timed to permit the fluid under treatment to enter the chamber 22 during this intake stroke of the piston 23. Once the operation of the transducer 20 is begun on a continuous basis, the pessure of the uid within the chamber 22 will force the piston 23 downwardly, as viewed in FIGURE 1. The resulting uid pressure thus supplements the downward biasing force of the compression springs 72.

The rotation of the power shaft 40 through one hundred and twenty degrees continues the intake stroke of the piston 23 until the piston has moved downwardly a distance 2A; twice the amplitude A of the cam lobes 53 and 54. Then, the rotation of the power shaft -40 through the next one hundred and twenty degrees will again cause the balls 60 to roll a distance equal to one-half L or sixty degrees, and bring the balls 60 into engagement with the cam lobes 53 and 54, as seen in FIGURE 3A, to force the piston 23 upwardly into the chamber 23. The resulting upward power stroke of piston 23 also occurs through a distance equal to twice the amplitude of the cam lobes 53 and 54 (2A). The piston 23 will thereby apply a pressure force to the fluid contained in the chamber 23, and the fluid will be pumped or compressed, depending upon the intended application of the transducer 20. Again, the valving means 24 is timed in any well-known manner (not shown) to allow the compressed or pumped fluid to exhaust from the chamber 22 at the desired time during the cycle of piston 23. When the transducer is employed as a compressor or pump, the drive mechanism 50 therefore converts the rotary motion of the power shaft 40 directly into reciprocating motion of the piston 23.

To utilize the transducer 20 as either a two-cycle or four-cycle engine, the spark plug 26 is provided, and the valving means 24 is arranged by suitable means (not shown) to permit the proper sequence of intake, compression, power and exhaust stages for the piston 23.-Furthermore, the transducer 20 is provided with standard engine cranking and flywheel components (not shown) which begin the initial intake and compression strokes of the engine, as well-known to those skilled in the art. The cranking of transducer 20 will therefore again begin the rotation of the power shaft 40 and the cam 51 with respect to the piston 23 and the cam 52. In order to drive the power shaft 40 clockwise, as viewed from FIGURE 1, the conventional cranking and flywheel components are arranged to crank the power shaft 40 and the cam 51 in a clockwise direction. On the other hand, if it is desired to drive the power shaft 40 in a counterclockwise direction, the shaft 40 and the `cam 51 are initially cranked in a counterclockwise direction.

After cranking of the transducer 20, any compressed air-fuel mixture confined within the chamber 22 will be ignited at the proper time by the plug 26, and the piston 23 will be driven downwardly in the chamber 22, as viewed in FIGURE 1. During this power stroke the piston 23 forcefully urges the connected cam 52 against the balls 60 and causes the balls 60 to roll along the opposed cam lobes 53 and 54, as previously described. Since the piston 23 and the cam 52 are prevented from rotating by the engaged grooves and splines 64 and 65, as seen in FIGURE 1, the rolling of the balls 60 induced by the power stroke of the piston 23 will cause the cam S1 and the power shaft 40 to rotate with respect to the cam 52. When the transducer 20 is adapted as an engine, the drive mechanism 50 therefore operates to directly convert the reciprocating motion of the piston 23 into rotary motion of the power shaft 40. Of course, it will be apparent that substantially the same operation would result if the transducer 20 is adapted to operate as a hydraulic motor.

The drive mechanism 50 in accordance with this invention therefore converts the rotary motion of the power shaft 40 directly into reciprocating motion of the piston 23, and vice versa, Without the need for any conventional piston crankshafts or connecting rods and the like. The fluid transducer 20 is therefore a compact and lightweight power unit having very high power output and fluid displacement characteristics.

More particularly, when the transducer 20 having the three-lobed cams 51 and 52 is employed as a pump or 75 compressor, one revolution of the power shaft 40 by any input power source will cause the balls 60 to engage with the opposed lobes 53 and 54 of the cams 51 and S2 three times. As a result, the piston 23 is moved within the chamber 22 through three strokes, or one and one-half cycles, for each revolution of the power shaft 40. Each revolution of the power shaft 40 will therefore displace or compress more fluid, as compared to pumps or compressors having standard crankshafts and the like, which would produce only one cycle of the piston 23 for each revolution of the input power shaft 40.

A similar advantage results from the use of transducer 20 as an internal combustion engine or as a hydraulic motor, since the transducer 20 requires three strokes of the piston 23 to rotate the power shaft 40 through one revolution. Thus, the transducer 20 is arranged to provide more power strokes of the piston 23 for revolving the power shaft 40 at a given speed, and the shaft will have a high horsepower output.

A further feature of the transducer 20 in accordance with this invention is that the reciprocating motion of the piston 23 is transmitted to the revolving shaft 40,k or vice versa, solely by the rolling engagement of the balls 60 with the opposed cams 51 and 52. The cam drive mechanism 50 of the transducer 20 thus eliminates rigid loading members such as bearing and crankshaft pins and the like, .and greatly reduces friction losses in the transducer. The transducer 20 therefore has a very high mechanical efficiency. Moreover, the transducer 20 has a very high loading capacity, since the elimination of all rigid bearing surfaces and the transmission of force between the piston 23 and the power shaft 40 solely by rolling action of the balls 60 allow the piston 23 to be subjected to very substantial fluid forces or loads.

1 It will be apparent to those skilled in the art that the amplitude and wave length L of the cam lobes 53 and 54 can be readily selected to adapt the transducer 20 to suit particular applications. The relative spacing and the configuration of the lobes 53 and 54 could also be changed. In addition, the transducer 20 can be modified by varying the number of balls 60 and opposed cam lobes 53 and 54, as long as the number of balls 60 does not exceed the number of opposed cam lobes.

The drive mechanism 50 is further operative to effectively connect the reciprocatory piston 23 to the rotary power shaft 40 when one of the opposed cam surfaces 51a or 52a is planar. It has been found that increased loading capacity and high mechanical efficiency will attend such a construction as long as the possibility of sliding friction between the balls 60 and the opposed planar and lobed cam surfaces, 51a or 52a, is substantially eliminated. Accordingly, it has been found that a planar cam surface is operative with an opposed lobed cam surface having a small cam angle (angle X in FIGURE 3) if the tangent of the cam angle does not exceed the coefficient of friction of the balls 60 on the opposed cam surfaces 51a and 52a.

Pump and compressor construction FIGURES 4 through 9 illustrate a specic construction of a fiuid displacement device embodying the features of the present invention, including a drive mechanism for directly converting the rotating motion of an input shaft into reciprocating motion of a piston. Although this embodiment of the invention will be referred to as a pump, it will be appreciated by those skilled in the art that the structure and principles of operation are also suited for use in a uid compressor or hydraulic motor.

Referring to FIGURE 4, a uid pump in accordance with this invention is generally indicated by the reference numeral 100. The pump comprises four similar pumping sections 101, 102, 103 and 104 which are joined in series by a frame structure formed from end plates and 111, and connecting rods 112. Each of the pumping sections 101, 102, 103 and 104 have a common power input shaft 115, and further have a fluid inlet port 116.

A manifold 117 joins each of the inlet ports 116 to a common inlet conduit 118. As seen in FIGURE 7, the opposite side of the pump 100 is provided with similar fluid outlet ports 106 joined to a common outlet manifold 107, for discharging the uid pumped by each of the pumping sections 101, 102, 103 and 104 to a suitable uid reservoir. As further shown in FIGURE 7, the outlet ports 106 and inlet ports 116 are provided with spring-loaded check valves 109 and 119, respectively, which control the ow of fiuid into the pump 100. More specifically, the inlet check valves 119 will function to admit uid to pump 100, and the outlet check valves 109 will function to discharge fluid from the pump 100.

The pump 100 is also provided with a volume control mechanism 120 permitting the displacement or fluid output of the pump 100 to be varied within a predetermined rangefThe control member 120 comprises a pair of sectors 121 and 122 mounted upon the pump 100 by a control shaft 123 and a pair of brackets 124 and 125. As seen in FIGURES 4 and 5, the lower portion of each sector 121 and 122 is provided with a row of gear teeth 127, and a handle 126 is connected to the control shaft 123 to permit the control mechanism 120 to be manually operated, if desired.

Referring to FIGURES 5 and 9, the pumping sections 101, 102, 103 and 104 of pump 100 are substantially similar in contruction, and each includes a pair of opposed annular piston members 130 and 140. Both of the pistons 130 and 140 in each pumping section of pump 100 are extended over the common input shaft 115, and are reciprocated within the pumping sections by the action of a drive mechanism, generally indicated by the reference numeral 150.

Referring to FIGURE 5 in more detail, the input shalt 115 is supported by the end plate 110 within a suitable bushing 170, and extends axially through each of lthe pumping sections 101 and 102. Although it is not shown in FIGURE 5, the shaft 115 likewise extends through the pumping sections 103 and 104, andv is supported at its other end by a suitable bushing provided in the other end plate 111. A retaining ring 171 is fitted within a groove 172 in the shaft 115 and engages with the end plate 110 to prevent the shaft 115 from shifting axially within the pump 100.

Referring to FIGURES 5 and 7, each of the pumping sections 101, 102, 103 and 104 defines a cylindrical opening 180 which receives the substantially identical opposed annular -pistons 130 and 140. The pistons 130 and 140 are fitted over the input shaft 115, and are biased apart by a compression spring 183. In addition, a cylindrical sleeve 184 is fitted over the shaft 115 between the pistons 130 and 140 and the spring 183 in a manner which permits the shaft 115 to freely rotate with respect to the sleeve 184. The cylindrical opening 180 and the cylindrical sleeve 184 therefore define an annular piston chamber 185 between the pistons 130 and 140. Suitable inside and outside piston rings 186 and 187, respectively, are provided on the pistons 130 and 140 to assure that the annular chamber 185 will be properly sealed.

As further seen in FIGURES 5 and 7, the annular piston chamber 185 in this embodiment is enlarged by providing the pumping sections 101, 102, 103 and 104 with an annular groove 188 which is in direct fluid communication with the chamber 185, The pistons 130 and 140 are therefore capable of reciprocating within the pumping sections of pump 100 to impart a pumping force to any fluid contained within the respective annular piston chambers 185. It will tbe apparent from'FIGURES 5 and 9 that each of the pumping sections 101, 102, 103 and 104 are of su-bstantially identical construction, with the exception that the axial 4positioning of the pistons 130 and 140 with respect to each other are reversed in pumping sections 102 and 104, as compared to the positioning of the pistons 130 and 140 in the pumping sections 101 and 103.

The annular pistons 130 and 140 are also provided with means to restrain the rotation of the pistons within the pump during the pumping operation. In this regard, each of the -annular pistons 130 includes a set of equallyspaced peripheral bosses 205, each of which includes a circular yball groove 206 extending axially with respect to the piston 130. In addition, an annular ball ring 207 is radially disposed above the bosses 205 in each of the pumping sections 101, 102, 103 and 104, as indicated in FIGURE 5. The ball rings 207 include spaced ball bearings 208 engaged within the grooves 206 on the bosses 205 and the rings 207 are securely pinned to the pump 100 by suitable pins 209. The -ball bearings 208 therefore permit the pistons 130 to reciprocate axially within the cylindrical openings 180 of each pumping section, but restrain the pistons 130 from rotation.

Referring now to FIGURES 5, 8 and 9, each of the annular pistons 140 is also provided with grooved bosses 220 circumscribed by a ball ring 221. The ring 221 also carries ball bearings 222 which engage the piston bosses 220 and allow the piston 140 to move with respect to the ring 221 in an axial direction only. However, in comparison with the rotatably fixed ball rings 207 of the pistons 130, the ball rings 221 for each of the pistons 140 is joined by suitable pins 223 to a rotatable annulus 230. The annulus 230, which extends around the input shaft 115, therefore joins the adjacent pistons 140 together, and permits the pistons 140 in adjoining pumping sections 101 and 102 of the pump 100 to lbe rotated in unison. Although not shown in FIGURE 5, the adjacent pistons 140 in pumping sections 103 and 104, as seen in FIGURE 9, are also joined by an annulus similar to annulus 230.

As seen in FIGURES 5 and 6, the annulus 230 is provided with peripheral gear teeth 231 which engage with the teeth 127 on the sector 121. Another annulus (not shown) joining the pistons 140 in pumping sections 103 and 104 (FIGURE 9) is also provided with gears meshing with the teeth 127 on sector 122, as indicated in FIG- URE 4. By such an arrangement, the sectors 121 and 122 of the pump volume control mechanism will retain the annular pistons 140 in a predetermined circumferential position within the pumping sections 101, 102, 103 and 104, and prevent the pistons 140 from free rotation within their respective pumping sections. However, the control mechanism 120 will permit the pistons 140 to be selectively revolved within their respective pump-ing sections to vary the fluid displacement of the pump 100.

In order to reciprocate the annular pistons 130 and within their respective pumping sections, each of the piston-s 130` and 140 in the pump 100l is provided with a drive mechanism 150. As seen in FIGURES 5 and 9, each drive mechanism is similar in construction to the drive mechanism 50 shown in FIGURE 1, and comprises a pair of coaxially-opposed cam surfaces 151 and 152. The cam surfaces 151 and 152 define three equallyspaced cam lobes 153 and 154, respectively, of equal amplitude A and equal wave length L. In the pump 100, the cam surface 152 of each of the drive mechanisms 150 is formed integral with a rearward skirt portion of the annular pistons 130 and 140, as seen clearly in FIG- URES 5 and 9. Since the pistons 130 and. 140 do not rotate during the operation of the pump 100, the cam surfaces 152 therefore comprise the nonrotatable cam surrface for each of the drive mechanisms 150.

The pump 100 includes a series of annular cam members 155 to provide the pump 100 with means defining the remaining cam surface 151 of the drive mechanisms 150. Each cam member 155 is joined to the input shaft 115 adjacent one of the pistons 130 and 140, and defines the annular three-lobed cam surface 151 coaxially opposed to the cam surface -152 on each of the pistons 130 and 140. Furthermore, each annular cam member 155 is secured to the input shaft 115 by a suitable key engaged Within the shaft keyways 156 and is prevented from axial 9 movement on shaft 115 by retaining rings 157. The spaced cam members 155 and the cam surfaces 151 defined thereby will therefore rotate in unison with respect to the pistons 130 and 140 when the input shaft 115 is rotated.

Each of the drive mechanisms 150 has a set of three rolling members 160 frictionally engaged between the opposed cam surfaces 151 and 152. As seen in FIGURES 5, 6 and 9, the rolling members 160 in this embodiment are cylindrical discs, as compared to the balls 60 illustrated in FIGURES 1 through 3. A roller retainer 161 is rotatably secured to the shaft 115 between the cam surfaces 151 and 152 and maintains the rollers 160- in an equally-spaced position around the shaft 115. Moreover, each retainer 160 is fixed lfrom axial movement with respect to the shaft 115 -by the retaining rings 157, and the rollers 160 are mounted in almanner which permits each of the rollers 160 to move axially with respect to its retainer 161.

It is preferred that the movement of the retainers 161 and all of the rollers 160 with respect to each other be controlled so that the pumping sections 101, 102,103 and 104 operate in a coordinated fashion during the use of the pump 100. Accordingly, the adjacent ball retainers 161 within the -interiors of the pumping sections 101, 102, 103 and 104are joined for mutual rotation about the input shaft 115 by a strap link 162 and pins 1'63. The strap links 162 for the retainers 161 within pumping section 101 and a portion of pumping section 102 are shown in FIGURE 5, and the strap links 162 for all of the pumping sections of pump 100 are illustrated schematically in FIGURE 9. The normal planetary action of the rollers 160 engaged between the opposed cam surfaces 151 and 152 will thus drive the ball retainers 161 within the interior of the pumping sections at substantially one-half the speed of the input shaft 115.

The movement of the roller retainers 161a at both ends of the pump 100 is coordinated by a planetary mechanism 164. As seen in FIGURE 5, the planetary mechanism 164 comprises a pair of ring gears 165 and 166 and bevel gears 167. The ring gear 165 is fixed to the pump end plate 110 and the ring gear 166 is fixed for rotation with the input shaft 115. The bevel gears 167 mesh between the ring gears 165 and 166 and are connected to the adjacent roller retainer 161a by straps 168 and pins 169. By such an arrangement, the rotation of the input shaft 115 in this embodiment causes the bevel gears 167 to rotate around the ring gears 165 and 166 at one-half of the speed of rotation of the input shaft 115. The bevel gears 167 thereby function to drive the connected retainer 161a around the input shaft 115 at substantially the same reduced speed. The roller retainer 161:1 adjacent the other pump end section 111 is controlled in the same manner. Accordingly, the movement of the ball retainers 161:1 at the ends of the pump 100 is coordinated with the movement of the other ball retainers 161.

To begin the operation of pump 100, the inlet conduit 1'18 is connected to a fiuid source (not shown). rThe inlet manifold 117, as seen in FIGURES 4 and 7, will distribute the incoming iiuid to the inlet ports 116 for each of the pumping sections 101, 102, 103 and 104. The pressure of the incoming iiuid will depress the check valves 119 provided in the inlet ports 116 and will iiow into the piston chambers i185 of each of the pumping sections. The pumping action of the pump 100 can then be started by rotating the input shaft 115 at the desired speed by any suitable power source (not shown).

As seen in FIGURES and i9, the rotation of the input shaft 115 s-imultaneously rotates the annular cam members 155 and the lobed cam surfaces 151 defined thereby at the same speed. The rotating cam surfaces 151 will then frictionally engage with the adjacent rollers 160 and cause the rollers 160 and their respective retainers 161 to orbit around the input shaft 11'5. Since the rollers 160 are positioned in engagement between the 10 opposed cam surfaces 151 and 152, the rotation of shaft induces the rollers 160 to roll along the cam surfaces 151 and 1512, and the lobes 153 and 154 force the rollers t160 to shift axially with respect to the shaft 115. The cam member 155 defining the cam surface 151 is restrained from axial movement, so the orbiting rollers 160 will therefore reciprocate the annular pistons and 140 against the biasing force of springs 183. The reciprocating opposed pistons 130 and 140 will in turn exert a pressure force on any fluid contained within the annular piston chambers 185. As the pistons 130 and 140 are reciprocated toward each other, the fiuid contained within the annular piston chamber 185 will be pumped from the chamber through the check valve 109, as seen in FIGURE 7, and flow through the outlet port =106 into the common outlet manifold 107. The pumping stroke of the opposed pistons 130 and 140 is completed when the rollers 160 are engaged between the cam lobes 153 and 154, as seen in pumping section 101 of FIGURES 5 and 9.

After the pumping stroke is completed the rollers 160 will or-bit into a position between the opposed lobes 153 and 154, as seen in pumping section 102 of FIGURES 5 and 9. With the rollers 160 in such a position, the compression springs 183 will force the opposed pistons-130 and apart and permit an additional amount of fluid to fiow into the annular piston chamber 185. Continued rotation of the input shaft 115 will cause the pumping stroke to be repeated so that each of the pumping sections 101, 102, 103 and 104 of the pump 100 will Ibe in continuous operation.

As seen from FIGURES 5 and 7, the rolling engage ment between the rollers 160` and the opposed cam surfaces 151 and 152 will therefore reciprocate each of the piston 130 and 130 through a piston stroke equal to twice the amplitude of the lobes 153 and 154, or a distance 2A. Of course, this pist-on stroke can be modified by providing the opposed cam surfaces l151 and 152 with lobes of different amplitude. Furthermore, since the cam surfaces 151 and 152 in the pump 100 are provivided with three-spaced cam lobes 153 and 154, the pistons 130 and 140 will be driven through three strokes for each revolution of the input shaft 115. By such an arrangement, the pistons 130 and 140 will be driven through one and onehalf pumping cycles for each revolution of the shaft 115, and the pump 100 will have a substantial volumetric pumping capacity. Again, the number of lobes on each of the cam surfaces 151 and 152, their spacing, and their configuration can be varied to meet particular applications. The drive mechanisms thus provide the pump 100 with substantially the same advantages as the cam drive mechanism 50 provides for the previously-described transducer 20.

In addition, the useof the drive mechanisms 150 with the preferred mutually-opposed annular pistons 130 and 140 readily permits the pump 100 to be arranged for pumping a continuous and uniform ow of fluid. Accordingly, as seen i-n FIGURES 5 and 9, the various cam mechanisms 150 are arranged circumferentially about the input shaft 115 so that the operation cycles of the pumping sections 101, 102, 103 and 104 are phased with respect to each other. More specificially, the drive mechanisms 150 of the pumping section 102 is circumferentially advanced one-half of a lobe length L (60 degrees) with respect to the drive mechanisms 150 of the pumping :section 10'1. As a result, the reciprocating pistons 130 and 140 of the pumping section 102 will be completely outof phase with the reciprocating pistons 130 and 140 of the pumping section 101. The pumping section 101 will therefore begin a fluid intake stroke as the pumping section 102 begins a fluid discharge stroke.

In the same regard, the drive mechanisms 150 for the pumping section 103 are circumferentially advanced one- -fourth of a lobe length L (30 degrees) with respect to the drive mechanisms 150 of the pumping section 101, and the drive mechanisms 150 for the pumping section 104 are similarly advanced a distance equal to threefourths of a lobe length L (90 degrees). The pumping section 103 is thus halfway through a discharge stroke and the pumping section 104 is lhalfway through an intake stroke as the pumping section 101 begins an intake stroke. The resulting relationship between the pumping sections 101, 102, 103 and 104 is schematically illustrated in FIGURE 9. Such phasing of the pumping sections 101, 102, 103 and 104 balances the total liuid displacement of the pump 100 and assures that the volume of pumped uid discharging from the common outlet manifold 107 is constant and uniform.

The use of drive mechanisms 150 with the mutuallyopposed pistons 130 and 140 also permits the fluid displacement of the pump `100 to be infinitely varied by changing the axial movement r phasing of the pistons 130 and 140 with respect to each other. More specifically, the drive mechanisms 150 can be shifted circumferentially with respect to each other to infinitely vary the rel-ative axial movement of the pistons 130 and 140 from an in-phase condition where the pistons 130 and 140' are driven in opposite axial directions, to an out-of-phase condition where the pistons 130 and 140 are simultaneously driven in the same axial direction. When the pistons 130 and 140 are in phase, the iiuid within the chamber y185 will be subjected to a maximum pumping force as the pistons 130 and 140 are brought together, and the fiuid displacement of the pump 100 will be maximum. On the other hand, when the pistons 130 and 140 are completely out-of-phase and move in the same axial direction simultaneously, the fiuid within the piston chamber 185 will be subjected to no substantial compressive or pumpfing force. Thus, when the pistons 130 and 140 are in an out-of-phase condition the fiuid displacement of the pump 100 is substantially zero. In this embodiment the volume control mechanism 120 is operative to vary the phase of the pistons 130 and `140 within each of the pumping sections 101, 102, 103 and 104.

Referring to FIGURES 4 and 5, the volume control mechanism 120 includes the toothed sector 121 which is engaged with the Igear teeth 231 on the annulus 230 between the pumping sections 101 and 102. The control mechanism 120 also includes the toothed sector 122 which is similarly engaged with an annulus (not shown) between the pumping sections 103 and 104. The sectors 121 and 122 are joi-ned together by the control shaft 123 and can be simultaneously rotated by activating the control handle 126. The rotation of the sectors 121 and 122 will therefore operate to rotate the connected annulus 230 and the other annulus (not shown) around the pump input shaft 115.

As seen in FIGURE 5, the annulus 230 between pumpling sections 101 and 102 and the other annulus (not shown) between the pumping sections 103 and 104 are in turn connected to each of the adjacent annular pistons 140 by means of the connecting pins 223, the ball ring 221, and the ball bearings 222. The actuation of the control handle 126 thereby also rotates the piston 140 in each pumping section with respect to the opposed nonrotatable piston 130. The direction of movement of the pistons 140 when the control handle 126 is actuated in a clockwise direction, as viewed in FIGURE 4, is indicated by t-he broken directional arrows on each piston 140 in FIGURE 9.

In the arrangement illustrated in FIGURES and 9 the opposed pistons 130 and 140 in each pumping section are circumferentially positioned so that the lobes 154 on the piston cam surfaces 152 are in axial alignment. In such a position, the drive mechanism 150 for each of the pistons 130 and 140 will operate to reciprocate the pistons 130 and 140 in opposite axial directions. The opposed-pistons 130 and 140 for each 0f the pumping sections 101, 102, 103 and 104 are therefore in phase, and the fluid volume displaced by each pumping section will be maximum. On the other hand, when the control handle 126 is actuated to rotate each piston 140 with respect to the opposed piston through a circumferential distance equivalent to one-half of a cam lobe wave length L (60 degrees) the cam lobes 154 for the pistons 130 and 140 will be in opposite circumferential positions. As a result, the drive mechanism 150 for each of the pistons 130 and 140 will operate to reciprocate the pistons 130 and 140 in the same axial direction simultaneously. The pistons 130 and 140 for each pumping section 101, 102, 103 and 104 would then be out-of-phase, and the fluid displacement of each pumping section would be substantially zero. Of course, the volume control mechanism 120 can also be utilized to rotate the pistons and their integral cam surfaces 152 into any selected circumferential position between the extreme positions of maximum and minimum uid displacement. The volume control mechanism 120 thereby operates in conjunction with the drive mechanisms to provide the pump 100 with infinitely variable fluid displacement.

Engine Construction FIGURES 10 through l5 illustrate the construction of an internal combustion engine 300 embodying the features of the present invention. Although the illustrated engine 300 is a two-stroke Otto cycle engine, it will be apparent to those skilled in the art that variations in the system of the engine 300 could be readily accomplished Without departing from the present invention.

Referring generally to FIGURES 10 through l5, the engine 300 includes an engine housing 301 defining a cylindrical opening 310. A power output shaft 302 is supported by the engine housing 301 and extends within the housing 301 the full length of the opening 310. The engine 300 further includes a pair of mutually-opposed annular pistons 350 and 380 mounted around the power shaft 302 within the opening 310. The pistons 350 and 330 are capable of reciprocating in an axial direction during the operation of the engine 300 and are connected to the power output shaft 302 by a pair of drive mechanisms 450 and 480, respectively. The drive mechanisms 450 and 480 operate to drive the output shaft 302 by directly converting the reciprocating motion of the pistons 350 and 380 into rotary motion of the shaft 302.

Referring to FIGURE 10 in more detail, the engine housing 301 includes a plurality of cooling vanes 303 and is preferably constructed from a lightweight material having high heat-transfer properties so that the engine 300 may be air-cooled. The housing 301 also includes a paid of removable end plates 304 provided with axiallyaligned hubs 305 and bushings 306. The power output shaft 302 is rotatably supported by the housing within the bushings 306, but is restrained from moving axially by a set of retaining rings 307 engaged between the shaft 302 and the housing hubs 306.

A cylindrical sleeve 308 is fitted over the shaft 302 within the opening 310 between the pistons 350 and 380 and is mounted on a bushing 309 so that the shaft 302 can freely rotate with respect to the sleeve 308. The central portion of the opening 310 and the cylindrical sleeve 308 therefore define an annular piston chamber 315 between the opposed pistons 350 and 380. The end portions of opening 310` also define interior compartments 316 and 317 positioned behind the pistons 350 and 380, respectively. Suitable inside sealing rings 311 on the sleeve 308 and outside sealing rings 312 on the pistons 350 and 380 assure that the annular piston chamber 315 is properly sealed. However, the sleeve 308 includes a set of end apertures 313 which bring the compartments 316 and 317 behind the pistons 350 and 380 into tiuid communication with each other.

As seen in FIGURES l() and l5, the engine 300 includes a set of spark plugs 320 supported by the housing 301. The plugs 320 are in communication with the sealed annular piston chamber 315 through spark ports 321 and arc connected to a suitable ignition circuit (not shown).

The. plugs 320 will therefore generate a spark, and ignite any fuel-air mixture contained within the piston chamber 315 when the opposed pistons 350 and 380 are in a fully advanced position, as shown in FIGURE l0. The engine 300 is also provided with suitable carburation devices (not shown) which will produce thedesired fuel and air mixture within the piston chamber 315. l The engine 300 is further provided with valving which is operated by the reciprocating pistons 350 and 380 to scavenge the spent gases from the piston chamber 315 and to supply the chamber 315 with a fresh charge of fuel andv air. In this regard, the engine housing 301 defines an annular intake chamber 330, an annular exhaust chamber 335, and anannular intake port channel 340. As seen in FIGURE 10, the intake chamber 330 and the exhaust chamber 335 are defined between an external ycentvthe left piston 350.

Referring to FIGURES l and 13, the external hous- {ing wall 331 includes 'an inlet aperture 330:1 which brings the intake chamber 330 into .fluid communication with the atmosphere surrounding the engine 300. A suitable Carburation unit (not shown) can thus be joined to the aperture 330e to feed the desired air and fuel mixture into the intake chamber 330 during the operation of the engine 300. The housing 301 adjacent the intake chamber 330 is also provided with a series of circumferentially-spaced inlet slots 333 which bring the intake chamber 330 into fluid communication with the cornpartfnent 317 when the piston 380 is in a fully-advanced position, as seen in FIGURE 10.

The intake port channel 340y adjacent the left piston 350 includes circumferential slots 342' which bring the `channel 340 into fluid communication with the compartment 316 behind the piston 350, as seen in FIGURE 10. In addition, the intake port channel 340 is provided with al series of circumferential intake ports 343 which bring the channel 340 into tiuid communication with the piston chamber 315 when'the piston 350 is in a fullyretracted position, as seen in FIGURE 11.

As indicated by the arrows in FIGURES l0, 1l and 13,

'this arrangement permits a carburated fuel-air mixture to enter .the intake chamber 330 and ow through the slots 333 into the compartment 317 behind the piston 380. The fuel-air mixture can then flow through the end apertures 313 in the sleeve 308 and into the compartment 316 behind the left piston 350. The reciprocation of thel pistons 350 and 380 will thus precompress the fuel-air mixture in the compartments 316 and 317 during the operation of Ythe engine 300. Finally, the precompressed fuel-air mixture will ow into the intake port channel 340 through the slots 342 and will be charged into the piston chamber 315 through the inlet ports 343 when the piston 380 clears the ports 343, as seen in FIGURE 1l.

Referring to FIGURES and 14, the external housing wall 33.1 is further provided with .an outlet aperture 336 which brings the exhaust chamber 335 into fluid communication with the atmosphere surrounding the engine 300. Thus, a suitable exhaust manifold (not shown) can be secured to the outlet aperture `336 to receive the spent combustion gases expelled during the operation of the engine 300. The housing 301 adjacent the exhaust chamber 335 also includes a series of circumferential exhau'st ports`337, as seen in FIGURE 14, connecting the engine 300 will thus function as a power source for driving'the power output shaft 302 by means of the drive mechanisms 450 and 480. During such driving operation, the pistons 350 and 380 are preferably biased outwardly away from each other and are restrained from rotation. Accordingly, as seen in FIGURES 10, l1 and l2, the engine 300 includes a set of compression springs 400 positioned between the engine housing 301 and each of the pistons 350 and 380. Each piston 350 and 380 additionally includes a set of axial splines 401 which'engage with adjacent grooves 402 in the housing 301. The splines 401 and the grooves 402 thereby cooperate to prevent the pistons 350 and 380 from rotating during the operation of the engine 300. Y

The drive mechanisms 450 and 480 which drive the power output shaft 302 are positioned within the housing 301 adjacent the pistons 350 and 380, respectively., As seen in FIGURES 10 and l1, the drive mechanism 480 is positioned Within the compartment 317 at the right end of the engine housing 301 and connects the right piston 380 with the power output shaft 302. More particularly, the drive mechanism 480 includes an annular cam 481 which is secured by pins 482 to the adjacent portion of the piston 380. A second annular cam 485 is positioned coaxially with respect `to the cam 481 and is connected to a power shaft tiywheel 486 by suitable pins 487'. The annular cams 481 and 485 are substantially identical in construction and provide coaxially-opposed cam surfaces which each have three cam lobes of equal wave length and amplitude. The lobes for the cams 481 and 485 are preferably sinusodial in configuration, and are indicated in FIGURE 10 by the reference numerals 483 and 489, respectively.

In the same regard, the drive mechanism 450 is positioned within the compartment 316 at the left end of the engine housing 301 and connects the left annular piston 350 to the power output shaft 302. As seen in FIGURES l0 and ll, the drive mechanism 450 includes an annular cam 451 secured to the piston 350 by pins 452. The drive mechanism 450 further includes a second annular cam 455 positioned coaxially with respect to the cam 451 and connected to a second power shaft flywheel 456 by pins 457. The cams 451 and 455 are substantially identical to the cams 481 and 485 of the drive mechanism 480, and therefore define three opposed cam lobes, 453 and 459 respectively, which are sinusodial in configuration and which have equal amplitudes and wave lengths.

By this arrangement of the drive mechanisms 450 and 480, the cams 451 and 481 are restrained from rotation during the operation of the engine 300 by connection to the nonrotatable pistons 350 and 380, respectively. On the other hand, the cams 455 and 485 will rotate with the fllywheels 456 and 486 and the power input shaft 302. Each of the drive mechanisms 450 and 480 accordingly includes one rotatable annular cam, and one annular cam which is fixed from rotation.

The construction of the drive mechanisms 450 and 480 is completed by providing each drive mechanism with a set of three rolling members or balls 460. As seen in FIGURE l2, the balls 460 are mounted in equally-spaced positions within ball race apertures 46.1 provided in a ball retainer 462. The apertures 461 will permit the balls 460 to move axially with respect to the retainer 462. As seen in FIGURES 10 and ll, a ball retainer 462 is rotatably mounted on the output shaft 302 between the opposed cams in each of the drive mechanisms 450 and 480, with the balls 460 between the opposed cams. By this arrangement, the balls 460 will shift axially with respect to the ball retainers 462 and orbit about the power output shaft 302 during the operation of the engine 300. The balls 460 will therefore frictionally engage with and roll between the opposed cams of each drive mechanism 450 and 480, .and will convert the reciprocation of the pistons 350 and 380 into a force which rotates the cams 455 and 485 and the power output shaft 302. FIGURES 10 and 12 also illustrate that the ball retainers 462 are provided with vents 463 permitting the combustion gases of the engine 300 to circulate easily through the drive mechanisms 450 and 480.

In the preferred arrangement of the engine 300 the ilywheels 456 and 486 are connected to the output shaft 302 so that the lobes 459 and 489 on the attached cams 455 and 485 are in axial alignment. However, it is preferred that the piston 380 be secured within the housing 301 in a position rotatably advanced a small angle with respect to the opposed piston 350. The cam 481 attached to the piston 480 will thereby be disaligned with respect to the cam 451 on the opposed piston 450. More particularly, the lobes 483 on the cam 481 will be angularly advanced in comparison to the lobes `453 on the cam 451. The angular advance of piston 380 with respect to piston 350 is in the clockwise direction in this embodiment, and is illustrated in FIGURE 12 by the angle D. The magnitude of the angle D is preferably about fifteen degrees.

By this rotational advancement of the piston cam 481 with respect to the piston cam 451, the axial movement of the right piston 380 will lead the axial movement of the left piston 350 by a small distance, and the pistons 350 and 380 will be slightly out-of-phase with each other. The resulting axial distance by which the piston 380 will lead the piston 350 is indicated by the axial dimension d in FIGURE 11. This arrangement eliminates the possibility that the power stroke of the pistons 350 and 380 will begin when the drive mechanisms 450 and 480 are in an exact axial alignment and thus prevents the occurrence of a dead-center condition in the engine 300. This advancement of the piston 380 with respect to the piston 350 also improves the eiciency of the engine 300 by improving the scavenging action of the pistons, and preloads the drive mechanisms 450 and 480 so that the power output shaft 302 is readily driven in a clockwise direction.

With regard to the improved scavenging action of the pistons 350 and 380, the reciprocation of the piston 380 will lead the piston 350 by the axial distance d, as seen in FIGURE 11. As further seen in FIGURE 11, the piston 380 will thereby open the exhaust ports 337 of the engine 300 before the intake ports 343 are cleared by the piston 350. The spent combustion gases accumulated within the piston chamber 315 will thus begin exhausting from the chamber 315 before a fresh air-fuel charge is admitted by the intake ports 343. In addition, the exhaust ports 337 instantaneously before the opening of the intake ports 343 permits the pressure of the incoming fresh air-fuel charge to force the spent combustion gases with the chamber 315 out of the exhaust ports 337. The precompressed fresh air-fuel charge thereby effectively scavenges the exhaust gases from the chamber 315.

As mentioned above, the clockwise advancement of the piston 380 and the cam 481 attached thereto also preloads the drive mechanism 480 in a manner which assures that that the engine shaft 302 will be driven in a clockwise direction. This direction preloading is caused by the tendency of the balls 460 to seek or roll into a position between the lobes 483 and 489 of the opposed cams 481 and 485. The advancement of the cam 481 and its cam lobes 483 in a clockwise direction thereby causes the rolling balls 460 to orbit clockwise in order to reach a position between the cam lobes 483. Since the power stroke of the engine 300 forces the rotationally-advanced piston 380 outwardly before the piston 350, the drive mechanism 480 will therefore start rotating the power output shaft 302 in a clockwise direction before the other cam drive mechanism 45C'.

By such an arrangement, any possibility of dead-center condition for the engine 300 is eliminated and the engine 300 can be readily cranked in a clockwise direction by any suitable cranking mechanism (not shown). Similarly, one'of the pistons 350 or 380 can be rotatably advanced to the angle D in a counter-clockwise direction with respect to the nonadvanced piston, and the engine 300 would then be preloaded for rotating the power shaft 302 in a counterclockwise direction. Thepengine 300 could then be readily started by a cranking mechanism (not shown) which cranks the engine 300 in a counterclockwise direction.

In the engine 300 the rotational position of the opposed pistons 350 and 380 with respect to each other is fixed by the engagement between the piston splines 401 and the housing grooves 402, as seen in FIGURE 10. However, it would be appreciated by those skilled in the art that the engine 300 can be readily provided with a control mechanism similar in construction and operation to the volume control mechanism of the pump 100, as illustrated in FIGURES 4 and 5. Such a control mechanism would be operative to rotate one of the pistons 350 or 380 and change the axial alignment of the piston cams 451 and 481. The direction and degree of the angular advancement D could then be selectively adjusted from outside of the engine housing 301.

A control mechanism for the engine 300 similar t0 the volume control mechanism 120 of the pump 100 would also permit the phasing of the pistons 350 and 380 to be inlinitely varied from an in-phase condition, where the pistons 350 and 380 are reciprocated in opposite axial directions, to an out-of-phase condition, where the pistons 350 and 380 reciprocate in the same axial direction simultaneously. Such changes in the phase of the pistons 350 and 380 would vary the volumetric capacity of the piston chamber 315 during the compression stroke, and would thus provide the engine 300 with an infinitely variable compression ratio.

To briefly describe the yoperation of the engine 300, a suitable cranking mechanism (not shown) would be energized to drive the output shaft 302 and the flywheels 456 and 486 in a clockwise direction, as viewed in FIG- URE 12. When the opposed pistons 350 and 380 reach their advanced position as seen in FIGURE 10 a carburated air-fuel mixture will enter through the inlet slots 333, and circulate behind the pistons 380 and 350. The retraction of the pist-ons 350 and 380 into the pistion illustrated in FIGURE 11 will operate to precompress the air-fuel mixture behind the pistons, and will expose the intake ports 343. The precompressed air and fuel will then be charged into the piston chamber 315 through the intake ports 343. The first movement of pistons 350 and 380 from a position shown in FIGURE 10 to the position in FIGURE ll therefore completes the intake and precompression stages of the two-stroke cycle engine 300.

As the cranking mechanism (not shown) continues to reciprocate the pistons 350 and 380 the pistons will again advance toward each other and further compress the air and fuel contained in the piston chamber 315. When the pistons 350 and 380 again reach the fully-advanced position shown in FIGURE 10 the spark plugs 320 will ignite the air-fuel mixture and begin the power stroke of the engine 300. The power stroke will force the pistons 380 and 350 outwardly, and thereby force the balls 460 of the drive mechanisms 450 and 480 to begin rolling along the opposed cam lobes 453, 459, 483 and 489. The force of the balls 460 will thereby rotate the rotatable cams 455 and 485, their attached flywheels 456 and 486, and the power shaft 302. Since the piston 380 is slightly advanced with respect to the piston 350, the drive mechanism 480 will begin rotating the flywheel 486 initially in the angular direction in which the piston 380 is advanced.

The continued outward movement of the piston 380 will first open the exhaust ports 337 and allow the combustion gases to begin exhausting from the piston chamber 315. Almost instantly thereafter, the movement of the piston 350 will expose the intake ports 343 and allow a fresh charge of precompressed air-fuel mixture to enter the piston chamber 315. As this fresh charge enters the chamber 315 it also scavenges through the chamber and forces any residual spent gases out through the cx- 17 haust ports 337. A cycle of the engine 300 is thereby completed. Since the drive mechanisms 450 and 480 incorporate three-lobed cams in this embodiment, the pistons 350 and 380 will travel through three complete axial strokes when producing one revolution of the output shaft 302. The engine 300 thus repeats its power cycle one and one-half times for each revolution of the shaft 302 and transmits substantial power to the shaft 302.

Although the invention has been described with a certain degree of particularity, it should be understood that the present disclosure has been made only by way of example. Consequently, numerous changes in the details of construction and the combination and arrangement of components as well as the possible modes of utilization, will be apparent to those familiar with the art, and may be resorted to without departing from the spirit and scope of the invention as claimed.

I claim:

1. In a uid transducer including a reciprocatory nonrotatable piston member positioned in communication with a fiuid chamber and a rotary power member, the combination thereof with a drive mechanism for operatively connecting said piston member to said power member, said drive mechanism comprising: a rst cam member connected to said piston member; a second cam member 25 connected to said power member and spaced adjacent saide first cam member; said first and second cam members defining opposed annular cam surfaces with each of said cam surfaces including a cam lobe projecting toward the opposed cam surface; said lobes having substantially equal lobe amplitudes and lobe wave lengths; a rolling member disposed between said rst and second cam members in frictional engagement with said opposed annular cam surfaces; and means retaining said rolling member in engagement with said cam surfaces, said retaining means permitting said rolling member to freely orbit between said first and second cam members and engage with said lobes while rolling along each of said opposed annular cam surfaces as said piston member reciprocates with respect to said power member.

2` In a fluid transducer including a pair of reciprocatory piston members arranged in an opposed position within a common fluid chamber, means restraining said -pistons from rotating freely within said chamber, and

further including a rotary power member, the combination thereof with a drive mechanism for operatively connecting each of said piston members to said power member, said drive mechanism comprising: a first ca rn member connected to the rearward portion of each piston member; a second cam member spaced adjacent each of said first cam members and connected to said power member; said adjacent first and second cam members defining adjacently opposed annular cam surfaces with each of said cam surfaces including a cam lobe projecting toward the adjacent opposed cam surface; said lobes on said adjacent opposed cam surfaces having substantially equal lobe amplitudes and lobe wave lengths; a rolling member disposed between each of said first and second cam members in frictional engagement with said adjacently opposed annular cam surfaces; and means retaining each of said rolling members in engagement with said adjacently opposed cam surfaces, said retaining means permitting said rolling member to freely orbit between said first and second cam members and engage with said lobes while rolling along each of said adjacently opposed annular cam surfaces as said piston members reciprocate with respect to said power member.

3. The invention in accordance with claim 2 wherein said piston members comprise opposed annular pistons coaxially disposed about said power shaft and wherein said annular cam surface defined by said first and second cam members are coaxially arranged with respect to said annular piston members.

4. A fluid displacement device comprising a housing delining a plurality of piston chambers, valving means for controlling the ow of fluid through said chambers, a pair of opposed pistons mounted for reciprocation in each of said chambers, means to restrain said pistons from rotating freely within said chambers, a power shaft rotatably supported by said housing and a drive mechanism operatively connecting each of said opposed pistons to said power shaft for reciprocating said pistons in response to rotation of said power shaft, said drive mechanism comprising a first cam member connected to the rearward portion of each of said pistons, a second cam member spaced adjacent each of said first cam members and connected to said power shaft, said adjacent first and second cam members defining adjacently opposed annular cam surfaces each having a cam lobe projecting toward the adjacent cam surface, said opposed cam lobes having substantially identical lobe amplitudes and lobe wave lengths, a rolling member disposed between each of said first and second cam members in frictional engagement with said adjacently opposed annular cam surfaces, and means retaining said rolling members in engagement with said adjacently opposed cam surfaces and permitting said rolling members to freely orbit between said adjacent first and second cam members and engage said lobes while rolling along each of said adjacently opposed annular cam surfaces when said second cam members are rotated with respect to said first cam members by said power shaft.

5. A fluid displacement device in accordance with claim 4 wherein said lobes of the first cam members connected to one pair of pistons are revolved with respect to said lobes of the first cam members connected to another pair of pistons to reciprocate said one pair of pistons out of phase with said other pair of pistons.

6. A fiuid displacement device in accordance with claim 4 including means to selectively revolve one of said first cam members for each of said pair of opposed pistons with respect to the other first cam members to vary the axial positioning of the lobes on said revolved first cam members with respect to the lobes on said other first cam members, thereby permitting the phase of reciprocation of one pair of said opposed pistons to be selectively varied with respect to the phase of reciprocation of another pair of said opposed pistons.

7. In an internal `combustion engine having a housing defining a combustion chamber and having valving means to control the flow of combustion :gases through saidchamber, a piston mounted for reciprocation in said chamber, means restraining `said piston from rotating freely within said chamber, a power member rotatably supported by said housing, and a drive mechanism operably connecting said power member to said piston for rotating said power member in response to reciprocation of said piston, said drive mechanism comprising a first cam member connected for reciprocation with said piston, `a second cam member connected for rotation with said power member and spaced adjacent said first cam member, said first and second cam members defining opposed annular cam surfaces with each of said cam surfaces including a cam lobe projecting toward the opposed cam surface, said opposed lobes having substantially equal lobe amplitudes and lobe wave lengths, a rolling member disposed between said first and second cam members in frictional engagement with said cam surfaces, and means retaining said rolling member in engagement with said cam surfaces and permitting said rolling member to freely orbit between said first and second cam members and engage with said opposed lobes while rolling along each of said opposed annular cam surfaces when said first cam member is reciprocated with respect to said second cam member.

8. In an internal combustion engine having a housing defining a combustion chamber and having valving means to control the fiow of combustion gases through said chamber, a pair of opposed pistons mounted for reciprocation in said chamber, means restraining said pistons from rotating freely within said cham'ber, a power member rotatably supported by said housing, and a drive mechanism operatively connecting each of said opposed pistons to said power member for rotating said power member in response to reciprocation of said pistons, said drive mechanism comprising a first cam member connected to the rearward portion of each of said pistons, a second cam member spaced adjacent each of said first cam members and connected to said power member, said adjacent first and second cam members defining adjacently opposed annula-r cam surfaces each including a cam lobe projecting toward the adjacent cam surface, said opposed lobes having substantially equal lobe amplitudes and lobe wave lengths, a rolling member disposed between each of said first and second cam members in frictional engagement with said adjacently opposed cam surfaces, and means retaining each of said rolling members in engagement with said adjacently opposed cam surfaces and permitting said rolling members to freely orbit between said adjacent first and second cam members and engage said lobes while rolling along each of said adjacently opposed annular cam surfaces when said first cam members are reciprocated with respect to said second `cam members.

9. The invention in accordance with claim 8 wherein each of said opposed annular cam surfaces include a plurality of lobes of substantially equal lobe amplitude and lobe wave length, and wherein said drive mechanism includes a plurality of rolling members uniformly disposed between said adjacently opposed annular cam surfaces and retained in rolling engagement with said cam surfaces.

10. The invention in accordance with claim 8 wherein said annular cam surfaces are in substantially coaxial -alignment and wherein a lobe of one of said first cam members is revolved with respect to a lobe of the other first cam member to cause one of said pistons to reciprocate in advance of the other opposed piston.

11. In an internal combustion engine, a housing delining a annular combustion chamber, valving means to control the flow of combustion gases, a pair of opposed annular pistons mounted for reciprocation within said charnber, means restraining said pistons from rotating freely within said chamber, a power shaft rotatably supported by said housing and extending through said chamber in substantially coaxial alignment with said annular pistons, and a drive mechanism operatively connecting each of said pistons to said power shaft for rotating said shaft in response to reciprocation of said pistons, said drive means comprising a first cam member connected to the rearward portion of each of said pistons, a second cam member spaced adjacent each of said first cam members and connected to said power shaft, 'said adjacent first and second cam members defining adjacently opposed annular cam surfaces in substantially coaxial alignment with said power shaft, each of said cam surfaces including a plurality of substantially identical cam lobes projecting toward the adjacently opposed cam surface, a plurality of rolling members uniformly disposed between each of said first and second cam members in frictional engagement with said adjacently opposed cam surfaces, and means to retain said rolling members in engagement with said adjacently opposed cam surfaces, said retaining means permitting said rolling members to freely orbit between said adjacent first and second cam members and engage with said lobes while rolling along each of said adjacently opposed annular cam surfaces when said first cam members are reciprocated with respect to said second cam members.

12. The invention according to claim 11 wherein said valving means directs the incoming combustion gas to circulate within said housing into compartments disposed behind each of said opposed pistons `before said incoming 2i) combustion gas enters said combustion chamber so that the reciprocation of said pistons within said housing precompresses said incoming gas.

13. The invention in accordance with claim 1 wherein each of lsaid cam surfaces includes a plurality of cam lobes projecting toward the opposed cam surface with the opposed lobes having substantially equal lobe amplitudes and lobe wave lengths, and wherein said drive mechanism includes a plurality of rolling members uniformly disposed between said opposed annular cam surfaces and retained in frictional rolling engagement with said cam surfaces.

14. The invention in accordance with claim 1 wherein said fluid transducer comprises a fluid displacement device including valving means for controlling the tiow of fluid through said liuid chamber.

15. The invention in accordance with claim 2 wherein each of said lcam surfaces includes a plurality of cam lobes projecting toward the opposed cam surface with the opposed lobes having substantially equal lobe amplitudes and lobe wave lengths, and wherein said drive mechanism includes a plurality of rolling members uniformly disposed between said opposed annular cam surfaces and retained in frictional engagement with said opposed cam surfaces.

16. The invention in accordance with claim 2 wherein said fluid transducer comprises a fluid displacement device including valving means for controlling the flow of fluid through said fiuid chamber.

17. A fluid displacement device in accordance with claim 16 including means to selectively revolve one first cam member with respect to the other first cam member to vary the axial position of said lobe on said revolved first cam member with respect to said lobe on said other first cam member and vary the phase of reciprocation of said opposed pistons.

18. An internal combustion engine in accordance with claim 7 wherein each of said cam surfaces includes a plurality of cam lobes projecting toward the opposed cam surface with the opposed lobes having substantially identical lobe amplitudes and lobe wave lengths, and wherein said drive mechanism includes a plurality of rolling members uniformly disposed between said opposed cam surfaces and retained in frictional rolling engagement with said cam surfaces.

19. The invention in accordance with claim 8 wherein said internal combustion engine includes means to selectively revolve one first cam member with respect to the other first cam member to vary the axial position of said lobe on said revolved first cam member with respect to said lobe on said other first cam member and vary the phase of said opposed pistons, t0 permit the compression ratio of said engine to be selectively varied.

Saw cam motion article, pages 68-73 inclusive.

WENDELL E. BURNS, Primary Examiner. 

